Bias Select: In general, higher bias resistors -> lower electronic noise. However, higher resistance = larger voltage drop due to leakage current.
Our natural leakage currents at operating voltage of 60V range from 18nA (MSPad 15A) to 320nA (Design I 13). At maximum expected rate of 100Hz, our signal induced leakage current is 
8.9nA. Hence our voltage drop range is 0.54V to 6.6V with 20MOhm resistors.
Since we are not electronically noise limited with GeV signals, we decided to choose the lower resistance in case any detectors have bad leakage currents to ensure a good comparison.

For Silicon detectors: p-side collects positive signals, n-side collects negative signals.

Finally, the expected signal energy for each detector is:
 - 1st Si pad -> 2.2GeV
 - 7th Si pad -> 2.5GeV
 - CsI scint  -> 1.3GeV
 - GAGG scint -> 0.9GeV
 - BGO scint  -> 129MeV
As a result, all Si preamps were set to 5GeV max range (MSI#1 Ch1-8 & MSI#2 Ch1-4). CsI & GAGG will use 4GeV range preamps (MSI#2 Ch7-8). BGO will use 330MeV preamps (MSI#2 Ch5-6).

Attached is the final MSI-8 preamp setup using the above settings.